can you compost fish?
Only buried in a hot pile, fermented in bokashi, or handed to a curbside program — fish is the strongest animal attractant in a kitchen.
breaks down in 1–3 months in a hot pile under heavy carbon cover
C:N ≈ 6:1
which bins can take it?
- hot pile caution
- cold pile no
- worm bin no
- bokashi yes
- tumbler caution
- curbside yes
- hot pile: Open a hole in the hot core, drop the scraps in, and cap with a foot of sawdust or leaves.
- tumbler: Sealed drums keep animals out but rarely hold the heat fish needs — small amounts only.
why?
Fish scraps sit near the bottom of the carbon-to-nitrogen scale, down in chicken-manure territory, which makes them both a powerful pile activator and a powerful smell. Fish oils oxidize fast, and the amines released as the protein breaks apart are what raccoons, bears, and neighborhood cats key on. Under a foot of sawdust or leaves that signal all but disappears, which is exactly how farm mortality composting works.
how to prep it
- Chop or grind large pieces before burying
- Bury at least 12 inches down in the pile center
- Cover with twice as much sawdust, straw, or leaves as you think you need
- Freeze scraps until pile-building day
watch out for
- In bear country no burial depth makes fish safe in an outdoor pile — use bokashi or freeze it for curbside pickup.
- Compost that has taken raw fish should heat to 131°F before it touches food crops; if your pile never warms up, put that batch on shrubs and flowers.
often confused with
- Dead Fish — A whole pet or bait fish is the same material at larger scale — burial depth matters even more.
quick answers
Is it true you can bury a fish under tomato plants?
It's the old plant-a-fish-with-the-corn trick, and it does work as slow fertilizer — but go a foot down and expect raccoons to test the spot for a few nights. Composting it first is tidier.
Do fish bones break down?
Much faster than mammal bones. They're thin and soft, mostly gone within a season in a hot pile, which is why fish bone meal is a standard organic phosphorus fertilizer.